使用异步/等待在猫鼬5上有问题

Question

我一直试图从猫鼬中重构代码，说明如何与lambda一起使用它，但一直在失败。我认为，这与我使用异步/等待的不当程度有关。根据日志，conn对象没有按预期进行初始化。总之，这是我的密码。

db.js

const mongoose = require('mongoose');
const uri = 'mymongoURL';

module.exports.initDb = async function()  {
    return mongoose.createConnection(uri, {
    bufferCommands: false, // Disable mongoose buffering
    bufferMaxEntries: 0 // and MongoDB driver buffering
   });
}

index.js

const mongoose = require('mongoose');
let conn = null;
const db = require('./db');

exports.handler = async (event,context,callback) => {
context.callbackWaitsForEmptyEventLoop = false;

if (conn == null) {
  conn = await db.initDb();
  console.log("conn is still null: "+ conn == null);
  conn.model('Foo', new mongoose.Schema({
    promo: {
      type: String,
    }
  }, { collection: 'foo', timestamps: { createdAt: 'created_at', updatedAt: 'updated_at' } } ));

  conn.model('Test', new mongoose.Schema({ name: String }));
}

    const FM = conn.model('Foo');
    let fooObj = new FM({promo:"Zimmer!"});
    fooObj.save(function(err, response) {
      console.log(err);
    });

    const M = conn.model('Test');
    let zim = new M({name:"Zim!"});
    zim.save(function (err, result){
    });
};

对于我如何使用异步/等待不当，我事先表示歉意。

Answer 1

对于db.js，您忘记添加对createConnection函数的等待。等待应该在异步功能中使用。

const mongoose = require('mongoose');
const uri = 'mymongoURL';

module.exports.initDb = async function()  {
    return await(mongoose.createConnection(uri, {
    bufferCommands: false, // Disable mongoose buffering
    bufferMaxEntries: 0 // and MongoDB driver buffering
   }));
}